MOSCOW — A Russian business mogul allied with President Vladi­mir Putin threatened Friday to sue media outlets for reporting accusations that the tycoon held a secret meeting with a senior Russian government official aboard his yacht in 2016.

The allegations, stemming from an investigation by Russian opposition leader Alexey Navalny, come as Russia heads toward a presidential election next month that is expected to keep Putin in office.

Oleg Deripaska, who owns one of Russia’s largest industrial groups, said in a statement that the investigation by Navalny was part of a “planned campaign aiming to damage my reputation.”

In a video posted to YouTube, the opposition leader accused ­Deripaska of bribing the official, Sergei Prikhodko, a deputy prime minister and former aide to Putin, by entertaining him on his yacht with several women described as escorts. The video has attracted more than 1.2 million views but no official reaction.

A spokesman for Putin declined to comment on the video Friday during a daily call with journalists.

Russian magnate Oleg Deripaska at U.S. Independence Day celebrations at the residence of the U.S. ambassador in Moscow in 2015. (Alexander Zemlianichenko/AP)

“I want to warn the media against the dissemination of these mendacious accusations,” Deripaska said in his statement, which was emailed to news organizations including The Washington Post. “I will severely suppress any attempts to create and disseminate false information flow using all legal measures and will defend my honor and dignity in court.”

The statement was also posted on the Instagram account of Deripaska, who has an estimated net worth of $6.7 billion, according to Forbes.

Business media outlet RBC said Friday that Prikhodko responded to inquiries about the video in a statement. “I would have answered him like a man, but we will remain within the legal framework,” the statement said. Prikhodko went on to say that he did not know Paul Manafort, former campaign chief for Donald Trump and a figure in a U.S. special prosecutor’s investigation into Russian attempts to influence the 2016 U.S. presidential election.

“This political loser once again tried to arrange a provocation and promote himself, confusing everything that did and didn’t happen — from my friend [Deripaska] to U.S. President Trump and Manafort, whom I don’t know personally.”

Navalny’s investigation was based on open-source data and Instagram photographs and videos posted by a woman named Nastya Rybka, who has written a book about her escort work.

In an interview on Russian television last year, Rybka said she was hired by a modeling agency to spend time on Deripaska’s yacht. The investigation linked the yacht trip with salacious details in ­Rybka’s book and speculated that the meeting could be tied to accusations of Russian interference in the 2016 U.S. presidential election.

Ilya Shumanov, a vice president for Transparency International in Russia, called the investigation “very interesting” for its use of social media to chronicle alleged ties between wealth and power in Russia.

What you need to know about Paul Manafort's ties to Russia. (Thomas Johnson/The Washington Post)

“A lot of people know that there are these kinds of talks between high Russian officials and oligarchs, but, of course, it’s not often possible to show it quite like this,” he said.

It is possible that paying for travel and entertainment could be construed as a bribe in Russia.

Navalny responded to Deripaska on Instagram, writing: “What are you calling the false accusations? Was government official Prikhodko not aboard your yacht? Did he not fly there on your plane?”

Despite the clip’s popularity on social networks, it appeared unlikely to lead to any kind of official investigation or derail what seems to be Putin’s surefire reelection for a fourth term as president.

“These clips give additional weight to Navalny as an opposition politician,” said Oleg Kashin, a popular journalist who often speaks critically of the government. “But the fight against corruption in Russia has already become a kind of game. Society has gotten used to the fact that bureaucrats live dishonestly.”

Lawyers for Deripaska sued the Associated Press last year over an article that said he had paid Manafort for work aimed at advancing the goals of the Russian government and Putin.